Interactions of glutathione tripeptide with gold cluster: Influence of intramolecular hydrogen bond on complexation behavior

Tehrani, Z. A ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1021/jp2080226
  3. Publisher: 2012
  4. Abstract:
  5. Understanding the nature of the interaction between metal nanoparticles and biomolecules has been important in the development and design of sensors. In this paper, structural, electronic, and bonding properties of the neutral and anionic forms of glutathione tripeptide (GSH) complexes with a Au 3 cluster were studied using the DFT-B3LYP with 6-31+G**-LANL2DZ mixed basis set. Binding of glutathione with the gold cluster is governed by two different kinds of interactions: Auâ€"X (X = N, O, and S) anchoring bond and Au··•·•H-X nonconventional hydrogen bonding. The influence of the intramolecular hydrogen bonding of glutathione on the interaction of this peptide with the gold cluster has been investigated. To gain insight on the role of intramolecular hydrogen bonding on Au-GSH interaction, we compared interaction energies of Au-GSH complexes with those of cystein and glycine components. Our results demonstrated that, in spite of the ability of cystein to form highly stable metal-sulfide interaction, complexation behavior of glutathione is governed by its intramolecular backbone hydrogen bonding. The quantum theory of atom in molecule (QTAIM) and natural bond orbital analysis (NBO) have also been applied to interpret the nature of interactions in Au-GSH complexes. Finally, conformational flexibility of glutathione during complexation with the Au 3 cluster was investigated by means of monitoring Ramachandran angles
  6. Keywords:
  7. Atom in molecules ; Basis sets ; Bonding property ; Conformational flexibility ; Cysteins ; DFT-B3LYP ; Gain insight ; Glutathiones ; Gold clusters ; Interaction energies ; Intramolecular hydrogen bond ; Intramolecular hydrogen bonding ; Natural bond orbital analysis ; Non-conventional hydrogen bondings ; Tripeptide ; Amino acids ; Gold ; Gold compounds ; Hydrogen bonds ; Peptides ; Quantum theory ; Complexation ; Oligopeptide ; Chemical structure ; Chemistry ; Hydrogen bond ; Glutathione ; Hydrogen Bonding ; Molecular Structure ; Oligopeptides
  8. Source: Journal of Physical Chemistry A ; Volume 116, Issue 17 , 2012 , Pages 4338-4347 ; 10895639 (ISSN)
  9. URL: http://pubs.acs.org/doi/abs/10.1021/jp2080226